Fluid actuated snap-acting gate valve



July 21, 1953 Filed Dec. 27, 1948- J. E. ELKINGTON 2,646,075

FLUID ACTUATED SNAP-ACTING GATE VALVE 2 Sheets-Sheet l I I V i l /O 5 1 o o o 25 /9 {26 0 4 Z? m V U o O 35 J a 45 rl J 1 30 11 a4 4 I L 3 E Q 6 63 i 3* /4 M J 2 i I INVENTOR. James L. [-lkingzon 3 4 BY y 1; 1953 J. E. ELKINGTON' 2,646,075

FLUID ACTUATED SNAP-ACTING GATE VALVE Filed D90. 27, 1948 r 2 Sheets-Sheet 2 IN V EN TOR. domes f F/k/ng/on 'A TTOAIIFYS Patented July 21, 1953 FLUID ACTUATED SNAP-ACTING GATE VALVE I James E. Elkingt'on, San Francisco, Calif.

Application December 27, 1948, Serial No. 67,287

This invention relates to a dish washing machine and particularly to a hydraulic actuator or prime mover for reciprocating a dish tray moving rack in and through the washing zone of said machine; said actuator beingmade to reciprocate by hydraulic pressure in alternating cycles.

An object of the invention is to provide an hydraulic actuator which includes a plunger made to reciprocate by applying hydraulic pressure in alternating cycles to opposite faces of the plunger through the instrumentality of a valve timer synchronized to operate with the plunger and to control its operation;

' In the accompanying drawings:

Fig. 1 is a side elevation, partly broken away, of a dish washing machine constructed in accordance with my invention, showing my hydraulic reciprocator operatively applied thereto.

Fig. 2 is a longitudinal sectionof an hydraulic actuator or prime moverconstructed in accordance with my invention, illustrated in its application to a slide rack on a dish washing machine, the plunger of the actuator being secured tothe rack while the actuator mechanism is fixed on one end of the washing machine structure.

Fig. 3 is an enlarged cross-section taken through the valve chamber on the 1ine 3-3 of Fig. 2.

Fig. 4 is an exploded view of the valve and its guide members. v

Fig. 5 is a fragmentary view on an enlarged scale of a part of the valve actuating mechanism.

Fig. 6 is a view in front elevation of the valve chamber without the valve. g

In detail the construction illustrated in the drawings comprises a dish washing machine which in its entirety is designated by the numeral I0. This dish washing machine includes, in addition to the necessary structural framework, a water tank I I, fluid spray pipes I2, a fluid pump I3 and a motor I4, a reciprocating rack I5 mounted over the tank I I and between the spray pipes I2 for moving trays I8 of dishes and the like through the washing zone on the parallel guides I9 which extend longitudinally through the machine. v

The dirty dishes or other articles to be washed are placed by hand in trays I8 and the loaded trays are placed on the entrant end of guides I9. The guides I9 are formed of spaced complementary angle bars and beneath said guides the reciprocating rack I5 is slidably mounted. The rack I5 is of known construction, and it is provided, at spaced intervals between the ends thereof, with counterweighted pawls 25 pivotally 6 Claims. (01. 137-701) mounted thereon. The upper end 26 of each pawl is adapted to engage ribs or serrations (not shown) on the under side of the dish trays gages the dish trays I8 and advances'them, with an intermittent movement, along the tray guides E9. on the return stroke of the rack I5 the pivoted pawls 25 disengage from the dish trays but automatically swing upwardly into contact with the dish trays upon the start of the forward stroke of the rack I5.

The type of rack I5 hereinabove'described for advancing the dish trays through the wash zone is only one of many types of similar racks which might be utilized to be actuated by my reciprocating mechanism. For example, a rack swing-f ably supported, pendulum style, might also be actuated by my hydraulic actuator or a pair of parallel endless belts could be actuated intermittently by my prime mover for moving the dish trays through the machine. It is to be understood that while I have developed the prime mover particularly for its use on a dish washing machine, that the reciprocative impulses developed by it could be applied to or utilized on many other machines of a type and kin-d needing a reciprocative movement in some phase of their operations.

A cylinder 39 is mounted on a base 3] and is closed at the end opposite the base 3| by a cap 32a. The cap 32a is, secured to the base-3| by rods, welding or otherwise.

The cap 32a is drilled centrally with the axis fined. The outer end of the shaft 32, is fixed to.

the cross member 33 of the rack, while the inner end of the shaft 32, within the cylinder 39, has a plunger or piston 34 mounted thereon;

The shaft 32 is drilled axially at .35 and it is closed at one end by a solid plug 36 and at its other end it is provided with a hollow plug 31 which slidably receives an actuator rod 38. At one end the actuator rod is provided with an enlarged head 39 and at its other end it extends through the base 3| into a valve chamber 45.

The valve structure comprises a valve plate or slide valve 46 slidably confined between a pair of of the cylinder 36 to provide a bore in which a.

opposing. uides 4'! and 48, the upper guide 4'! being sweated into the valve chamber and the to provide an ovate slot 53 and spaced oil holes 54 and 55 and an ovate socket 56 disposed betweenv and aligned with the oil holes.

The outer end of the actuator rod 38 extends through a pin or cross member 51 to which it is secured by a set screw 58. The-pinl is free to slide in slot 53, and bearing against it are two sleeves 59, each of which is recessed at 66 to pro vide a bearing surface for the pin 5'! and at G! at right angles to the recess 60 for a purpose explained hereinafter. A rivet 62 is received within each sleeve 59 with its headseated in a recess 63 formed in the chamber 45 and is urged outwardly by a coil spring 6%. A washer 55a is slida'bly and rotatably mounted on the pin 5? as illustrated to balance the forces acting on the pin at the end of its travel.

The valve chamber i5 is provided with three oil holes 6", 66 and 6?. The inner hole 65 communicates through a duct Til with the inner end of the cylinder 30, and the outer hole 6? communicates through a duct H with the annular space 12 between the cylinder 39 and an outer cylinder or casing 13 and which communicates with the outer end of cylinder through a port it. The socket 56' and oil holes 5:3 and 55 formed in the valve 48 are such that, when the valve is in its extreme outer position as illustrated in Fig. 2, the inner oil hole 65 is aligned with the hole 5 3,

and hence the interior of chamber is in communication with the outer end of cylinder 3 Also, the oil holes 66 and 6? are in communication with each other through the socket 56. Obviously, when'the valve 46 is in its extreme inner position, the oil holes 65 and E5 will communicate with each other and the oil hole iii will be aligned with the hole in the valve; hence, the annular space '.'2 will communicate with the valve chamber 45.

A pump 89 driven by the motor it is provided, and'it pumpsoil from a sump 8! through a line 82 and-a line 83 to'the valve chamber d5. Oil is returned-through oil hole 55 and a line 8 3 to the sump 8L In operation the apparatus performs as follows: Oil is pumpedto the chamber' lfi as described, thus maintaining a fluid pressure therein at all times. Assuming the valve 518 to be in the position shown in Fig. 2, oil flows-through hole 54 formed in valve A5, oil hole formed in a valve chamber 45 and duct '54} into the outboard end of cylinder 30, causing piston 3A to move inwardly. Actuator rod 38 remains stationary, as doesvalve it, until plug 31 strikes head39, causing inward movement. of pin 57. As pin 5? moves'inwardly, springsii l are compressed and when pin 57 moves past dead center, these springs expand causing pin 5? to-snap inwardly very rapidly, carrying valve 4% with it to its oppositeor inward position. Meanwhile, oil passes from cylinder 36 through port l4 into the annular space 12, through duct 7!, oil hole Bl, socket oil hole 55 and line 84 back to the sump BI.

When the valve 38 reaches its inner position, oil will flow from chamber 45 through hole 55 formed in valve 46, oil hole 57, and'duct ll into annular space 12, through port l6 and into the inward end of cylinder 30, thus causing outward movement of piston 34. When plug 35 contacts head 39, it will move actuator rod 38 outwardly, thus causing corresponding movement of pin 5'! and valve 46 to restore the latter to its original position, thus completing a cycle of operation.

It will thus be apparent that a reciprocating cylinder has been provided which is specially well adapted to impart intermittent movement to a tray in a dish washing machine, but which also has a wider utility. Among the important advantages of the apparatus may be mentioned the following: The valving action is very rapid, and it will be noted that the arrangement of parts is such that the piston 34 has a relatively long travel corresponding to the requirements of a dish washing machine while the actuator rod 38 and pin El have a relatively short travel and the valve 56 an even shorter travel. This results in compactness of the unit and inactivation of the valving mechanism except for a brief interval during each stroke, thus reducing wear of parts. The slide valve 48 is such that wear does not, within reasonable limits, impair its efiiciency. Thus, springs 5| and balls 52 keep it in perfect alignment, and they serve the further purpose of providing enough frictional resistance to prevent the valve 46 from moving with the pin 57 until the same has passed dead center. This is important because in past designs difliculty has been encountered, especially after some usage and wear, because the valve would sometimes move slowly with the pin and would stop on dead center with the hydraulic pressure equal on both sides of the piston.

It will also be noted that the sleeves 59 are hollowed out at E0 to bear against and turn on the pin 5'5, and that they are also hollowed out at 6! at right angles'to the hollows 6E1, so as to accommodate the actuator rod 38 in either of its extreme positions. Thus, as illustrated, when the rod 38 is in its outermost position, the hollows or grooves 5| are cupped over the rod 38, thus allowing greater compactness of construction.

Also, as mentioned hereinabove, the washer 65a balances the forces acting on pin 5'! at the end of its travel. Thus, when the pin 5'? strikes one end of slot 53, in the absence of the washer 55a,

a torque would result tending to break or bend the pin. This is obviated by the washer 5511.

While I have shown th preferred form of my invention, it is to be understood that various changes may be made'in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desireto secure by Letters Patent is:

l. A valve structure of the character described, comprising a valve chamber having an inlet port andspaced outlet ports, a valve member slidable within said chamber to open either of said outlet ports and to close the other outlet port, said valve member being formed with a slot, and means for actuating said valve member comprising a reciprocable rod having a pin at one end received in said slot, and resilient radial members each bearing against said pin at one end and atthe opposite end against said valve-chamber and operable to compress as said pin approaches dead center and. to expand when said pin passes dead center so asto quickly slide said valve men her to its opposite position.

2. A valvestructure of the character described, comprising a valve chamber having an inlet port and spaced outlet ports, a valve member slidable within said chamber to open either of said outlet ports and close the other outlet port, said valve member being formed with an elongated slot, and means for actuating said valve member comprising a reciprocable rod having a pin at one end slidable in said slot, apair of radially disposed sleeves each bearing at its inner end against said pin and resilient means received Within the outer end of each said sleeve and bearing against the said valve chamber so as to compress as saidpin approaches dead center and thereby quickly slide said valve member to its opposite position.

3. A valve structure of the character described, comprising a valve chamber having an inlet port and spaced outlet ports, a valve member having an elongated slot formed therein, means within said chamber confining said valve member to sliding movement between a first position opening one of said outlet ports and closing the other and an opposite position closing said first mentioned port and opening the other port, said confining means including resilient means bearing against a surface of said valve member to frictionally engage the same and resist movement ber, a valve slidable therein and having a longitudinal slot formed therein, a reciproc'able mem ber, a pin supported by said member and slidably received at one end in said slot, and abutment means mounted on said pin externally of said slot operable to balance the forces acting on said pin on reaching either end of said slot.

5. A valve structure comprising a valve chamber, a valve slidable therein and having a longitudinal slot formed therein, a reciprocable member, a pin supported by said member and slidably received at one end in said slot, and a disclike member rotatably mounted on the other end of said pin operable to abut said chamber when said pin reaches either end of said slot.

6. In a valve a casing, a slidable valve plate Within said casing, a valve plate operating rod extending into said casing, a lost-motion pin and slot connection between said plate, rod and resilient means operable when the pin has been moved in either direction past the center of the slot to continue its movement to the end of the slot and thereafter to move the rod and plate together, said spring means comprising a spring toggle mounted within said casing, and comprising a pair of pivotally movable spring-urged telescopic members each engaging the pin at one end and the adjacent side of the casing at the other.

JAMES E. ELKINGTON.

References Cited in the file of this patent UNITED STATES PATENTS v Number Name Date 113,810 Stevens Apr. 18, 1871 142,292 Stevens Aug. 26, 1873 828,547 Hayden Aug. 14, 1906 892,833 Howard July 7, 1908 905,426 Haywood Dec. 1, 1908 958,492 Hardy May 17, 1910 1,282,841 Iles Oct. 29, 1918 1,770,931 Lathrop July 22, 1930 1,806,777 Wiley May 26, 1931 1,853,752 Wadsworth Apr, 12, 1932 2,110,393 Edwards Mar. 8, 1938 2,131,910 Vernon et a1. 1 Oct. 4, 1938 

